Gyu M. Lee

Information technology is an enabling factor affecting supply chain performance in Indian SMEs

Purpose – The purpose of this paper is to identify the success factors for supply chain in Indian small- and medium-scale enterprises (SMEs) and establish a causal relationship among them. In the present scenario, the SMEs are under huge pressure to achieve the supply chain competitive advantage and to improve operation and logistic effectiveness and, at the same time, remain tractable to the demand uncertainty and volatility in the market. To enhance the performance of supply chain in SMEs, the managers need to identify the internal as well as the external factors that affect the supply chain performance of SMEs in India. They need to understand the causal relationship of these factors. Design/methodology/approach – There may be a number of factors that are critical for achieving acceptable supply chain performance, and these factors have been identified by principal component analysis (PCA). In all, 29 factors have been identified by using PCA and the dominating 29 factors are categorized into 6 constru...

Spatial scheduling for large assembly blocks in shipbuilding

Development of a novel MIP model considering various tough constraints in practice.Development of space allocation method for spatial scheduling.Development of hierarchical heuristic algorithms with computational capability.Performance comparison between the MIP model and the heuristic.Robust computational times by the proposed algorithm with regard to the problem size. This paper addresses the spatial scheduling problem (SPP) for large assembly blocks, which arises in a shipyard assembly shop. The spatial scheduling problem is to schedule a set of jobs, of which each requires its physical space in a restricted space. This problem is complicated because both the scheduling of assemblies with different due dates and earliest starting times and the spatial allocation of blocks with different sizes and loads must be considered simultaneously. This problem under consideration aims to the minimization of both the makespan and the load balance and includes various real-world constraints, which includes the possible directional rotation of blocks, the existence of symmetric blocks, and the assignment of some blocks to designated workplaces or work teams. The problem is formulated as a mixed integer programming (MIP) model and solved by a commercially available solver. A two-stage heuristic algorithm has been developed to use dispatching priority rules and a diagonal fill space allocation method, which is a modification of bottom-left-fill space allocation method. The comparison and computational results shows the proposed MIP model accommodates various constraints and the proposed heuristic algorithm solves the spatial scheduling problems effectively and efficiently.

A novel coarse-to-fine registration approach for aligning partially overlapped 3D scanned data

ABSTRACT This paper proposes a novel method for register partially overlapped three-dimensional (3D) point sets when a complete 3D scanned model is constructed from partially scanned 3D point sets. 3D point sets are the most primitive and fundamental surface representations. 3D acquisition devices such as laser scanners and range image finders are popular sources for acquiring point clouds. With the availability of low cost and highly efficient 3D laser scanners, the popularity of such devices is increasing rapidly in various fields. Generally, a standard scanner can obtain only a partial data to build a complete 3D model of the object. These partially scanned 3D patches need to be aligned together in the same coordinate system to construct a complete 3D model, and this process is widely known as registration. A coarse-to-fine alignment technique is proposed to register two partially overlapped point sets. First, the overlapping regions using a novel sampling strategy are identified and the overlapping regions of two point sets are aligned together. Second, fine registration is carried out, in which an auxiliary pair and surface normal constraints are used to find reliable corresponding points in order to achieve higher accuracy.

Medical Relief Shelter Location Problem with Patient Severity under a Limited Relief Budget

Abstract It is an essential but difficult problem to provide effective and efficient medical or relief services to people in areas impacted by various anthropogenic and natural disasters. This study proposes a mathematical programming model to determine the locations of temporary medical relief shelters, as well as provide the required medical supplies from medical deployment centers effectively and efficiently under a limited relief budget. The severities and geographical locations of patients are considered in the problem. A mixed integer programming formulation has been proposed. The proposed model is hard to solve using a commercially available solver in a reasonable amount of time, especially for the problems of larger sizes. Hence, a greedy algorithm is proposed to solve the problem to generate good solutions in comparison with the solution obtained by LINGO. The computational results demonstrate the effectiveness and efficiency of the proposed methodology. Computational results under different scenarios are provided as well to demonstrate the validity of the proposed algorithm for various situations.

A Stochastic Programming Model for Multi-commodity Redistribution Planning in Disaster Response.

When a large-scale disaster occurs, a set of relief centers should be determined to accommodate evacuees and a variety of multi-commodity should be distributed to these relief centers to provide basic life support. Because the multi-commodity distribution at peacetime may be imperfect and unbalanced, the surplus commodities in some relief centers can be redistributed to other relief centers with shortages, to make the effective and efficient use of these commodities. This multi-commodity redistribution problem is also an important issue in the emergency management. Various uncertain elements include transportation network, supply and demand, making this problem a big challenge. To handle this problem, a two-stage mixed-integer stochastic programming model was proposed to facilitate this multi-commodity redistribution process. In our model, we define the dissatisfaction cost based on the relief center size, unmet demand and oversupply of commodity in the relief center. Then, our objectives are to minimize the total dissatisfaction cost in the first stage and minimize the total transportation time in the second stage, sequentially. Finally, a randomly generated numerical instance is tested and computational results show that the proposed model can provide effective and efficient decisions in the multi-commodity redistribution process.

Investigation of powder size effects on sintering of powder injection moulded 17-4PH stainless steel

ABSTRACT Densification behaviours of 17-4PH stainless steel powders (SUS17-4PH) of three different particle sizes during the sintering were investigated. The samples with different mean particle sizes of 3.17, 4.22 and 8.30 µm were prepared through powder-binder mixing, injection moulding, and solvent and thermal debindings. The in situ shrinkage data measured by dilatometry tests were treated to analyse the densification behaviour of each sample. In order to characterise the densification behaviour with a minimum set of experiments, the master sintering curve (MSC), as well-known and straight-forward approach, was employed. After constructing the MSCs for powders of different particle sizes, the effects of particle size on the densification were analysed in many respects including shrinkage, strain rate, apparent activation energy, and work of sintering.

Medical Relief Shelter Location Considering the Severity of Patients Under Limited Relief Budget

It is an essential but difficult problem to provide the effective and efficient medical or relief services to the people in the impact areas by various anthropogenic and natural disasters. This study proposes a mathematical programming model to determine the locations of temporary medical relief centers and provide the required medical supplies from medical deployment centers effectively and efficiently under the limited relief budget, considering the severities and geographical locations of patients. To demonstrate the validity of the proposed model for various situations, computational results under different scenarios are provided as well.

Linking soft computing to art: introduction of efficient k-continuous line drawing

Abstract Continuous line drawing (CLD) is a technique used in the field of art, in which the pen does not leave the paper until the sketch is completed. In this study, a novel technique, k-continuous line drawing (k-CLD), is proposed; this technique enables a visual image to comprise k closed non-intersecting lines. k-CLD involves the following challenges: 1) partitioning the target image into k regions, 2) stippling each region without distorting the target image, and 3) connecting the stippled dots in each region using a single closed, non-intersecting line. This study identifies and implements efficient algorithms to produce high-quality k-CLDs. Further, an improvement to the graph-based image segmentation algorithm has been proposed using the Minkowski distance to evaluate dissimilarity difference and demonstrated its effectiveness to partition the target image into k regions. Next, well-spaced stippled dots were generated in each region using a weighted Voronoi diagram. Finally, the stippled dots were connected by a single non-intersecting line, obtained by solving a traveling salesman problem (TSP) in each region. The metaheuristic to solve the TSP was an ant colony system algorithm. The proposed methodologies were tested on a wide variety of images to demonstrate their effectiveness and efficiency.

Supply Chain Decisions in Governmental Organizations

Apte, Khawam, Regnier and Simon (2017) discuss the challenge of maintaining a self-sustaining supply chain during a disaster response operation. A self-sustaining supply chain is characterized by the partial consumption of the supplies that it carries to the final user. It is a particularly relevant concern in military logistics and in disaster response operations when the delivery location lacks logistics infrastructure to support the logisticians who are bringing the supplies to its destination. For this reason, a substantial amount of the resources that enter in the self-sustaining supply chain are consumed within the supply chain, and only a fraction of the supplied resources arrive at the destination.

Development of hydrophobic forcep for robot surgery

The hydrophobic forcep for robot surgery was developed by powder injection molding and surface treatment. The processing conditions including filling behavior for powder injection molding was developed through MoldFlow simulation. After producing the surgical forcep, the surface treatment for hydrophobic surface was realized.